> The IOMMU_DEVONLY flag allows the caller to flag a mappings backed by > device-private buffers. That means other devices or CPUs are not > expected to access the physical memory region pointed by the mapping, > and the MMU driver can safely restrict the shareability domain to the > device itself. > > Will be used by the ARM MMU driver to flag Mali mappings accessed only > by the GPU as Inner-shareable. > > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> > --- > include/linux/iommu.h | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index d2f3435e7d17..db14781b522f 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -31,6 +31,13 @@ > * if the IOMMU page table format is equivalent. > */ > #define IOMMU_PRIV (1 << 5) > +/* > + * Mapping is only accessed by the device behind the iommu. That means other > + * devices or CPUs are not expected to access this physical memory region, > + * and the MMU driver can safely restrict the shareability domain to the > + * device itself. > + */ > +#define IOMMU_DEVONLY (1 << 6) > > struct iommu_ops; > struct iommu_group; This seems totally reasonable to me, but it is well-known that I'm not on good terms with the iommu subsystem. Let's wait for Robin to NAK :-P
